pgAdmin 4 commit: Make the Parameter grid use a workflow consistent wit

Make the Parameter grid use a workflow consistent with other grids. Fixes #1241

1. Altered variable control to make its UI consistent with privileges and Security labels.
2. Changed datamodel.js to handle duplicate rows at datamodel level and not UI/Control level. (See variable control for example)

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=pgadmin4.git;a=commitdiff;h=c7d25c33f2d2024622d2fd660f4f53864651e24d
Author: Harshal Dhumal <harshal(dot)dhumal(at)enterprisedb(dot)com>

Modified Files
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.../databases/templates/databases/js/databases.js | 2 +-
.../servers/roles/templates/role/js/role.js | 3 +-
.../server_groups/servers/static/js/variable.js | 445 +++++++++------------
.../servers/templates/macros/variable.macros | 4 +
web/pgadmin/browser/static/js/datamodel.js | 153 +++++--
.../debugger/templates/debugger/js/debugger_ui.js | 2 +-
6 files changed, 324 insertions(+), 285 deletions(-)